feat: multi-format 3D viewer with large-file OBJ streaming, Z-up, projection/outline UI

Three.js viewer supporting glb/gltf/obj/fbx/dae/ifc/ply via both server (SSR)
and drag&drop (CSR) paths.

- Streaming OBJ parser (src/viewer/objStream.ts) for files past the V8 max
  string length (>~1GB text) that OBJLoader can't handle; indexed geometry,
  per-vertex color from MTL Kd, float64 recenter baked in.
- In-viewer float64 recenter (objRecenter.ts) for huge CAD/survey coordinates
  (~1e8) so float32 vertex buffers keep precision (no cracked faces).
- Z-up right-handed world; Y-up formats rotated on load.
- OBJ+MTL+texture drag&drop (LoadingManager URL-modifier maps dropped images).
- OrbitControls ground-plane panning (road/rail alignment workflow).
- UI: Zoom Fit, perspective/orthographic toggle, feature-edge outline.
- DoubleSide for CAD OBJ; PLY mesh + point-cloud support.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tools/adaptive-smoke.mjs

@@ -0,0 +1,95 @@
+#!/usr/bin/env node
+/**
+ * tools/adaptive-smoke.mjs — empirically trigger the adaptive-quality downstep.
+ *
+ * Loads a heavy sample in headless Chrome (software GL = slow) + applies a CDP
+ * CPU throttle so the REAL measured fps sustains < 60. Captures the genuine
+ * `[hmwebviewer] adaptive quality -> tier N (pr=..)` console logs emitted by
+ * src/viewer/adaptiveQuality.ts, plus the live #.fps overlay text. Proves the
+ * <60fps → optimize path fires on real frame measurement (no logic patched).
+ *
+ * USAGE: node tools/adaptive-smoke.mjs [--url URL] [--asset PATH] [--throttle N] [--seconds S]
+ */
+import puppeteer from 'puppeteer-core';
+import { existsSync } from 'node:fs';
+
+const CHROME_CANDIDATES = [
+  'C:/Program Files/Google/Chrome/Application/chrome.exe',
+  'C:/Program Files (x86)/Google/Chrome/Application/chrome.exe',
+  'C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe',
+];
+function findBrowser() {
+  if (process.env.PUPPETEER_EXECUTABLE_PATH && existsSync(process.env.PUPPETEER_EXECUTABLE_PATH)) return process.env.PUPPETEER_EXECUTABLE_PATH;
+  for (const p of CHROME_CANDIDATES) if (existsSync(p)) return p;
+  return null;
+}
+
+function parseArgs(argv) {
+  const a = argv.slice(2);
+  let url = 'http://127.0.0.1:4173', asset = '/samples/ABeautifulGame.ktx2.glb', throttle = 6, seconds = 25;
+  for (let i = 0; i < a.length; i++) {
+    if (a[i] === '--url') url = a[++i];
+    else if (a[i] === '--asset') asset = a[++i];
+    else if (a[i] === '--throttle') throttle = Number(a[++i]);
+    else if (a[i] === '--seconds') seconds = Number(a[++i]);
+  }
+  return { url, asset, throttle, seconds };
+}
+
+const sleep = (ms) => new Promise((r) => setTimeout(r, ms));
+
+async function main() {
+  const o = parseArgs(process.argv);
+  const exe = findBrowser();
+  if (!exe) { console.error('[adaptive-smoke] No Chrome/Edge found.'); process.exit(1); }
+
+  const browser = await puppeteer.launch({
+    executablePath: exe,
+    headless: 'new',
+    args: ['--no-sandbox', '--use-gl=swiftshader', '--enable-webgl', '--ignore-gpu-blocklist'],
+  });
+  const page = await browser.newPage();
+
+  const tierLogs = [];
+  page.on('console', (m) => {
+    const t = m.text();
+    if (t.includes('adaptive quality')) { tierLogs.push(t); console.log('  LOG ' + t); }
+  });
+
+  await page.evaluateOnNewDocument(() => {
+    window.__hmwReady = null;
+    window.addEventListener('hmw:ready', (e) => { window.__hmwReady = e.detail; });
+  });
+
+  const target = o.url + '?model=' + o.asset;
+  console.log('[adaptive-smoke] ' + target + '  throttle=' + o.throttle + 'x  watch=' + o.seconds + 's  browser=' + exe);
+  await page.goto(target, { waitUntil: 'domcontentloaded', timeout: 30000 });
+  await page.waitForFunction('window.__hmwReady != null', { timeout: 60000 });
+  console.log('[adaptive-smoke] model loaded; applying CPU throttle + watching fps...');
+
+  const client = await page.target().createCDPSession();
+  await client.send('Emulation.setCPUThrottlingRate', { rate: o.throttle });
+
+  const start = Date.now();
+  while (Date.now() - start < o.seconds * 1000) {
+    await sleep(2000);
+    const state = await page.evaluate(() => {
+      const el = document.querySelector('.fps');
+      return { fps: el ? el.textContent : '(no overlay)', pr: window.__viewer ? undefined : undefined };
+    });
+    console.log('  t+' + Math.round((Date.now() - start) / 1000) + 's  overlay=' + state.fps + '  tierSteps=' + tierLogs.length);
+    if (tierLogs.length >= 3) break; // enough proof
+  }
+
+  await browser.close();
+
+  console.log('\n[adaptive-smoke] tier-change log lines captured: ' + tierLogs.length);
+  tierLogs.forEach((l) => console.log('  ' + l));
+  if (tierLogs.length === 0) {
+    console.error('[adaptive-smoke] NO downstep observed — fps stayed >=60 (raise --throttle or use a heavier asset).');
+    process.exit(2);
+  }
+  console.log('[adaptive-smoke] PASS — adaptive quality degraded on sustained <60fps.');
+}
+
+main().catch((e) => { console.error('[adaptive-smoke] Fatal: ' + (e && e.stack ? e.stack : e)); process.exit(1); });